Analytic and CFD Models for Transient Outburst Flow

Abstract

An analytic model (AM) describes the dynamical behavior of a Newtonian fluid that is suddenly released to the atmosphere from a pressurized vessel. The discharge process is a very fast transient phenomenon in which the liquid transits from rest to a highly turbulent motion, constituting a two-phase flow with a liquid–air interface. The AM has a number of parameters that can be adjusted to conform to experimental or simulation data. This AM is then used to assess the ability of some relevant computational fluid dynamics (CFD) turbulence models to simulate the fast transient behavior described by the AM. The detached eddy simulation (DES) k−ω shear-stress-transport with scale-adaptive-simulation (SSTSAS) turbulence model provides an acceptable agreement with the AM because it can reproduce the intense wall friction generated in the transient motion. The CFD results suggest that deceleration plays a very prominent role in generating turbulence near the wall. The cross-section velocity and turbulence fields profiles for the CFD model are also discussed.